"Informational Smallness and the Scope for Limiting Information Rents" (pdf), joint with Martin Hellwig, Journal of Economic Theory", Vol. 145 (6), 2010
"Beliefs, Payoffs, Information: On the Robustness of BDP Property in Models with Endogenous Beliefs" (pdf), joint with Martin Hellwig, Journal of Mathematical Economics, Vol. 51(3), 2014
"The Generic Possibility of Full Surplus Extraction in Models with Large Type Spaces" (pdf) , joint with Martin Hellwig, Journal of Economic Theory, Vol. 170 (7), 2017.
Supplementary material (pdf) and an informal graphical illustration to the result in Supplementary material (pdf)
"Selling Money on EBay: A Field Test for Social Preferences" (joint with Olga Gorelkina), (latest draft is available via email)
Abstract: To measure the prevalence of social preferences in a competitive environment, we conduct a natural field experiment on German eBay. Acting as a seller,
we offer Amazon gift cards with values from 5 to 500 euros. The randomly arriving buyers, unaware of the experiment, make us price offers according
to the platform's rules. Using a novel estimation technique, we extract from the observed distribution of offers two underlying distributions: offered shares of the trade surplus and beliefs about the seller's outside option. We then show that the social preferences are important in the field but to a lower extent than in the laboratory. Our experiment also demonstrates: (i) the amount of money at stake has no significant effect on offers; (ii) the subjects make poor use of public information;
(iii) the behaviour of East and West German subjects follows two separate patterns, likely due to the remaining cultural differences.
"Betting on Others' Bets: Unions of Generalized Cremer-McLean Mechanisms", (latest draft is available via email)
Abstract: We construct the generalized Cremer-McLean (GCM) mechanism where i’s participation fee depends not only on the valuations reported by -i at the second stage, but also on the choice of the participation fee by -i at the first stage. Such construction allows to exploit the convex hull property of beliefs whenever it appears in beliefs about beliefs rather than in beliefs about preferences. As such betting retrieves agents' entire hierarchies of beliefs, it reveals what is common knowledge among them. Hence, in an environment where the designer is uncertain about agents' type space but instead perceives as possible a finite or countable collection of type spaces, each verifying the convex hull property, he can propose a union of GCM mechanisms and to extract surplus across type spaces, i.e., regardless of absence of knowledge by the designer which type space agents share.
"On the Designer's Uncertainty, Families of Models and Generic Possibility of Full Surplus Extraction" (joint with Martin Hellwig),
Abstract: Heifetz and Neeman (2006) have shown that within a given convex family of of priors, if it contains at least one non-BDP prior, the full surplus extraction is impossible generically, from the measure-theoretic and geometric perspectives. In this paper we show that among all convex families of priors, the subset of convex families containing only full-surplus extraction priors (and so no non-BDP prior) is generic. Our result is topological. One implication of our result is that generically the designer's beliefs should put probability 1 only on full-surplus extraction models.
(this paper supersedes our earlier paper "On the Robustness of the BDP Property for Families of Incomplete-Information Models" )
"Wondering How Others Interpret It: Social Value of Public Information", 2013 (latest draft is available via email)
Abstract: This paper studies the social value of public information in environments without common knowledge of data-generating process. We show that the stronger is the coordination motive behind agents' behaviour, the more they would like to interpret private or public signals in the way that they suspect others are doing it. Consequently, negative impact of public communication noted by Morris and Shin (2004) can be amplified if agents believe that others take the public signal too literally and/or are too inattentive to their private signals. The social welfare is higher when each agent evaluates the precision of public signal correctly but believes that others did not understand the public signal at all, which suggests that there is a scope for the central bank to "obliterate" its communication in a specific way, by making it, e.g., sophisticated and technical.
"Endogenous Contract Enforcement Institutions", 2009 (latest draft is available via email)
Abstract: I study a large population of agents heterogenous in endowments who match to have a one-shot prisoners' dilemma trading game with each other. Each trading contract can be enforced via one of two competing contract enforcement institutions: a costless but asymmetric that imposes a punishment for cheating on poor agents but not on rich ones and a symmetric institution that imposes punishment for cheating independently of agents identities but which requires a collective investment into its capacity up-front. The paper shows: (i) Sometimes rich agents receive rents under the asymmetric system, but sometimes these are the poor who benefit from it; (ii) There exists an equilibrium where all agents, independently of their resources, pay to the fixed cost of the symmetric system provided it excludes non-contributors from enforcement of their contracts with contributors; (iii) The rate of cheating is always positive in contracts subject to asymmetric punishment and it is zero in contracts subject to impartial punishment.
Work in Progress
"Semi-Parametric Mechanism Design"
"Contagion-Proof Market Mechanisms" (with Lucie Menager)
"Details Behind Belief Hierarchies Matter" (joint with Martin Hellwig), 2009